Computationally Driven Discovery of Layered Quinary Oxychalcogenides: Potential p-Type Transparent Conductors?

Abstract

<p><i>n</i>-Type transparent conductors (TCs) are key materials in the modern optoelectronics industry. Despite years of research, the development of a high performance <i>p</i>-type TC has lagged far behind that of its <i>n</i>-type counterparts delaying the advent of “transparent electronics” based on fully transparent p-n junctions. Here, we propose the layered oxysulfide [Cu<sub>2</sub>S<sub>2</sub>][Sr<sub>3</sub>Sc<sub>2</sub>O<sub>5</sub>] as a structural motif for discovering novel p-type TCs. We have used density functional theory to screen the thermodynamic and dynamical stability and electronic structure of 24 compositions based on this motif, predicting 2 new p-type TCs and 8 other stable systems with semiconductor properties. Following our predictions, we have successfully synthesized our best candidate <i>p</i>-type TC, [Cu<sub>2</sub>S<sub>2</sub>][Ba<sub>3</sub>Sc<sub>2</sub>O<sub>5</sub>], which displays structural and optical properties that validate our computational models. It is expected that the design principles emanating from this analysis will move the field closer to the realization of a high figure-of-merit <i>p</i>-type TC.</p>

The Holey Grail of Transparent Electronics

“…8 However, a number of challenges remain, including the ability to control the optical (band gap) and conduction (mobility and carrier concentration) properties over a large range in addition to device considerations such as interface stability and work-function matching. This is where the work of Williamson et al 9 They used first-principles calculations to examine 24 distinct compositions and predict the electronic and structure changes. Among them, the substitution of Sr with Ba increases the lattice parameter a the most, making the dis-tance between Cu atoms longer.…”

“…From their compositional search, Williamson et al 9 Yang Xu, 1 Yuxing Yao, 2 and Xiaoguang Wang 1,3 To mimic the sweating functionality of human skin, Liu and coworkers have developed a liquid crystal (LC) polymeric networkbased artificial skin with programmable liquid secretion and excretion driven by radio frequency (RF) electrical fields.…”